Gas burner

ABSTRACT

The present invention provides a gas burner ( 10 ) including: a distributor means ( 50 ) having at least one distribution chamber to distribute an air gas mixture around said distributor ( 50 ), said burner ( 10 ) including a plurality of flame ports ( 70 ) through which said gas mixture can pass and be ignited; at least one injector ( 39 ) associated with said distributor ( 50 ), said at least one injector ( 39 ) being positioned to inject gas into said at least distribution chamber via a venture formed of a vertically directed passage and transition port ( 64 ) and at least one venturi extension extending away from said transition port ( 64 ). The present invention also provides manifold for a gas burner ( 10 ), said manifold having an upper wall ( 12 ) and a lower wall ( 16 ) held in spaced apart relationship by a peripheral wall to define a cavity there between, said manifold including means ( 38 ) to mount at least one injector ( 39 ) so as to deliver an air gas supply to a distribution means ( 50 ) and an inlet port ( 18 ) to allow connection to a supply of gas, which can pressurize said cavity, said upper ( 12 ) and said lower ( 16 ) wall being formed from relatively thin sections.

FIELD OF THE INVENTION

The present invention relates to gas burners for cooking stoves and inparticular to a gas burner suitable for use with a wok.

BACKGROUND OF THE INVENTION

Wok burners are in the main single injector designs and aim atconcentrating the heat at the centre of the burner, corresponding to thebottom of the wok. Such burners are known from documented prior artconstructions, such as those found in DE3918715 and similar designs,such as U.S. Pat. No. 6,688,882 and U.S. Pat. No. 6,089,219, as well asJP10-185212 and JP10-160127. However, it is common to theseconstructions that they require a fairly large space below the hobsurface to accommodate the injector. Also, most of these designs are notsufficiently adaptable, for instance in cases where it is desired to useone and the same burner configuration as the basis for a burner thatcould heat up a larger area of a cooking utensil, such as an ordinarycooking pot or frying pan. Even those documents among the above citedthat do indeed describe burners for larger areas require a large spacebelow the hob. It is the purpose of the present invention to provide gasburners which are adaptable for use in many variants, answering tovarious needs of heat distribution. It is a further purpose to providegas burners that do not take up much space below the hob surface.

Any reference herein to known prior art does not, unless the contraryindication appears, constitute an admission that such prior art iscommonly known by those skilled in the art to which the inventionrelates, at the priority date of this application.

SUMMARY OF THE INVENTION

The present invention provides a gas burner including: a distributormeans having at least one distribution chamber to distribute an air gasmixture around said distributor, said burner including a plurality offlame ports through which said gas mixture can pass and be ignited; atleast one injector associated with said distributor, said at least oneinjector being positioned to inject gas into said at least onedistribution chamber via a venturi formed of a vertically directedpassage and transition port and at least one venturi extension extendingaway from said transition port.

There can be two, three or four generally horizontal venturi extensions,which extend in separate directions away from said transition port.

The distributor means can have a generally cylindrical outer surface.

The distributor means can have at least two, or preferably three,equi-spaced inwardly extending arms.

The distributor means can include at least one radially outwardlyextending arm.

The flame ports direct streams of air gas mixture towards the centre ofsaid distributor.

The distributor can have an aperture having a clover leaf configuration.

The distributor means can be segmented whereby each segment has its owndistribution chamber and injector.

The distributor means can be segmented by means of segment walls betweenrespective segments.

The distributor means can be an assembly of separate or discretesegments which are assembled or otherwise joined together.

The separate or discrete segments can include interlocking formationsthereon so that adjacent burner segments can be assembled together.Alternatively or additionally, the separate or discrete segments areheld together as an assembly by means of a interaction with a burnercap. Alternatively or additionally a circumferential fixing meansassists in holding or holds said separate or discrete segments togetheras an assembly to form a distributor.

The distributor means can be segmented by means of gas flow from saidinjectors.

The segments can form one of the following: a cross shape with anarcuate or circumferential cross bar; a T shape with a convex arcuate orcircumferential cross bar; a T shape with a concave arcuate orcircumferential cross bar.

There can be two venturi extensions which form an arcuate orcircumferential shape.

There can be three venturi extensions which form a T shape with anarcuate or circumferential cross bar.

There can be four venturi extensions which form a cross shape with anarcuate or circumferential cross bar.

The at least one venturi extension can be formed as part of saiddistributor means.

The at least one venturi extension can be formed in a cap which ispositioned on top of said distributor means.

The burner can include a cap which is positioned on top of saiddistributor means.

The flame ports can be formed in one or more walls of said distributormeans.

The flame ports can be formed in a cap which is positioned on top ofsaid distributor means.

The at least one venturi extension can have one or more occludingstructures associated therewith for directing and or baffling said airgas mixture in its flow from said transition port to said flame ports.

The occluding structures can comprise a wall or ridge like formationextending away from said at least one venturi extension.

The distributor means can have at least one air entry port per injector.

There can be a plurality of air entry ports per injector.

A plurality of air entry ports can be formed in a side wall of saiddistributor means.

At least one air entry port can have a larger cross sectional area atintermediate regions by comparison to side regions of said air entryports.

At least one air entry port can be positioned in said wall of saiddistributor means so as to be located adjacent to said injector.

Each said injector can be shielded by a portion of a wall of saiddistributor means to prevent air passing in through said air entry portfrom disturbing the operation of said injector.

The air entry ports can be located between respective arms of saiddistributor means, and respective injectors are located so that they arealigned with the direction of radial extension of said arm.

The burner can include a trivet which is aligned with said arms, so asto overlie said arms.

The arms can have a flame port arrangement whereby the axis of saidflame ports on a respective arm is generally at an acute angle to theradial direction of extension of a respective arm.

The arms can extend away from said distributor means at an angle ofinclination or declination away from an imaginary horizontal plane.

The distributor means can be mounted on a manifold including a gas inletwhich communicates with a cavity in said manifold, said injectorscommunicating with said cavity.

The cavity can be convex shaped whereby the height of said cavity at theouter periphery is of a height greater than at the centre of saidcavity.

The manifold can have its top surface concave in shape, so as to collecttowards the centre of said base spillage which occurs during cooking.

The distributor means can have an internal and an external perimeter,with inwardly directed ports in said internal perimeter and outwardlydirected ports in its external perimeter.

The at least one venturi extension can be oriented so as to be generallyhorizontal.

The present invention also provides a manifold for a gas burner, saidmanifold having an upper wall and a lower wall held in spaced apartrelationship by a peripheral wall to define a cavity therebetween, saidmanifold including means to mount at least one injector so as to deliveran air gas supply to a distribution means and an inlet port to allowconnection to a supply of gas, which can pressurise said cavity, saidupper and said lower wall being formed from relatively thin sections.

The upper wall can have a convex surface protruding into said cavity.

The manifold includes one or more ports adapted to receive said at leastone injector nozzle.

The upper wall can have a generally concave surface on the outer upperside thereof.

The upper surface of said manifold can also function as a cup to receivespills when cooking.

The present invention further provides a gas burner comprising onedistributor means having at least two discrete distribution chamberstherein, each chamber having communication with flame ports andincluding a venturi to supply an air gas mixture thereto; said burnerhaving only one manifold to conduct gas to respective injectors for eachventuri from a single gas supply connection to said manifold, each ofsaid chambers having a radially extending portion, which extendsinwardly towards the centre of said burner, whereby between the ends ofrespective radially extending portions there is provided an unobstructedspace.

Each radially extending portion can include at least two sides which aregenerally parallel.

Each chamber can also include two oppositely extending circumferentialor arcuate portions.

The chamber can also include a radially outwardly extending portion.

The burner can include a cap.

The distributor means or said cap can include a multiplicity of saidflame ports.

The flame ports can be formed by a combination of formations located onsaid distributor means and said cap.

The chamber can include at least one venturi extension which defines aperipheral channel to deliver air gas mixture to flame ports.

The cap can include at least one venturi extension which extends intosaid chamber to define a peripheral channel to deliver air gas mixtureto flame ports.

Each venturi can include a vertical passage which opens into at leastone generally horizontal venturi extension which extends away from saidvertical passage in the direction of each respective extending portionof said chamber.

The at least one generally horizontal venturi extension can be formed insaid distributor means.

The at least one generally horizontal venturi extension can be formed inan underside of a cap.

The distributor means can be an assembly of separate or discretesegments which are assembled or otherwise joined together.

The separate or discrete segments can include interlocking formationsthereon so that adjacent burner segments can be assembled together.Alternatively or additionally, the separate or discrete segments areheld together as an assembly by means of a interaction with a burnercap. Alternatively or additionally a circumferential fixing meansassists in holding or holds said separate or discrete segments togetheras an assembly to form a distributor.

The present also provides a gas burner including a distributor havingflame ports in a wall portion of said distributor and or in a cap whichwill cooperate with said distributor, said distributor also including atleast two venturis with each venturi having a respective injectorassociated therewith located internally of and near to a wall portion ofsaid distributor, said distributor including at least two generallyelongated air inlet ports which are located in said wall, said portshaving a longitudinal axis which extends circumferentially around saiddistributor, said ports including at their extremities a reduced crosssectional area when compared to the central portions of said port.

A respective injector can be located between opposing ends of said airinlet ports near to a wall portion of said distributor to preventradially inwardly flowing air from interacting with said injector.

The injectors and said air inlet ports can be arranged with respect tosaid distributor so that a main stream of radially inwardly flowing airpasses through said transition port as secondary air for said flameports.

The injectors and the air inlet ports can be arranged with respect tosaid distributor so that air passing through said air inlet ports whichwill be used as primary air by said injectors approaches said injectorsin a generally circumferential direction from said air inlet ports.

The air inlet ports can provide an opening which increases in height toa maximum and then decreases, in circumferential direction around saiddistributor.

The air inlet ports can be one of the following: eye shaped; diamondshaped; half eye shaped, triangular; a circular segment.

The present invention further provides a gas burner including adistributor means having at least one chamber to distribute an air gasmixture around said distributor means, said burner including a pluralityof flame ports through which said gas mixture can pass and be ignited;at least one injector associated with said distributor means, said atleast one injector being positioned to inject gas into said at least onechamber via a respective vertically directed converging passageterminating with an transition port which has communication with saidchamber, a venturi being formed in part by said converging passage andsaid transition port with a final part of said venturi being formed byat least one venturi extension which acts upon a generally horizontalflow of said air gas mixture flowing from said transition port, saidtransition port having at or near its rim two or more occludingstructures associated therewith for directing and or baffling said airgas mixture in its flow from said transition port to said flame ports.

The occluding structures can comprise a wall or ridge like formationextending away from said protrusion and or said protrusion extensions.

The occluding structures can have a castellated appearance.

The occluding structures are formed on said distributor means or in acap associated with said distributor means or by a combination of both.

The flame ports can be formed on said distributor means or in a capassociated with said distributor means or by a combination of both.

Extending away from said transition port there can be at least twoventuri extensions.

The occluding structures can be located near to the edges of saidventuri extensions.

The venturi extensions can be formed either on said distributor means orin a cap associated with said distributor means or by a combination ofboth.

The occluding structures can taper toward their extremities.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described, by way ofexample only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an assembled gas burner;

FIG. 2 is an exploded view of the burner of FIG. 1;

FIG. 3 is a plan view of the burner of FIG. 1;

FIG. 4 is a cross section through the line IV-IV of FIG. 3;

FIG. 5 is a perspective view of a distributor used with the burner ofFIG. 1;

FIG. 6 is an underneath perspective view of the distributor of FIG. 5;

FIG. 7 is a larger scale cross section (similar to FIG. 4) of theassembled burner of FIG. 1, showing air, gas and air/gas mixture flowpaths;

FIG. 8 is a perspective view of another distributor similar to that ofFIG. 5;

FIG. 9 is a perspective view of another distributor, similar to that ofFIG. 5 with outer circumferential burner ports;

FIG. 10 illustrates a perspective view of another distributor similar tothat of FIG. 9;

FIG. 11 illustrates an enlarged perspective view of a portion of FIG. 10around the horizontal portion of the venturi;

FIG. 12 illustrates a perspective view of a burner having the inwardlyextending arms at an angle of inclination to the horizontal;

FIG. 13 illustrates a diametrical cross section through the burner ofFIG. 12;

FIG. 14 illustrates a perspective view of a burner similar to that ofFIG. 12 having the inwardly extending arms at an angle of declination tothe horizontal;

FIG. 15 illustrates a diametrical cross section through the burner ofFIG. 14;

FIG. 16 illustrates a plan view of an assembled burner of previousFigures and a cooperating trivet;

FIG. 17 illustrates a front elevation of the burner and trivet of FIG.16;

FIG. 18 illustrates a schematic of a burner segment of the burnersillustrated in the previous Figures;

FIG. 19 illustrates a schematic of another burner segment;

FIG. 20 illustrates a schematic of a further burner segment;

FIG. 21 illustrates a schematic of another burner segment;

FIG. 22 illustrates a burner having a distributor which will allow aspiral or helical flame effect to be produced when the burner is inoperation;

FIG. 23 illustrates a cross section through a burner showing flameports, venturi extensions and occlusion ridges formed in the undersideof a burner cap; and

FIG. 24 illustrates a cross section through a burner showing flameports, venturi extensions and occlusion ridges formed in a combinationof a distributor and a burner cap.

DETAILED DESCRIPTION OF THE EMBODIMENT

Illustrated in FIGS. 1 to 7 is a burner 10 which is an assembly ofseveral components including a manifold 15 which forms the base of theburner 10. The manifold 15 is an assembly of a manifold top member 14and a manifold bottom member 16. The manifold top member 14 has itsupper surface generally concave and thereby forms a cup 12. The manifoldbottom member 16 has a threaded female gas supply connection 18 and acut out portion 20 which receives the downwardly projecting side wall ofthe boss 32 on the base of manifold top member 14 to fit therein. Thepurpose of the boss 32 will be discussed below.

The nature of the manifold top member 14 and manifold bottom member 16is that they can be manufactured from relatively thin sections makingthem relatively simple to manufacture by any one of several methods suchas injection moulding, casting or pressing.

The manifold bottom member 16 has four downwardly extending supports 24which rest against the upper surface of a stove base (not illustrated)or burner box to support the manifold 15 when mounted in a stoveenclosure. Two of the supports 24 have locating lugs 25 extendingdownwardly therefrom, as each are to be inserted in similarly shapedapertures on a stove enclosure.

The manifold bottom member 16 is effectively a cover which sealinglysits within a similarly shaped recess 26 located within the lowermostrim 28 of the manifold top member 14. As can be seen from the crosssections of FIGS. 4 and 7, the manifold bottom member 16 issubstantially horizontal or straight in its construction. This iscontrasted with the central portion 28 of the manifold top member 14which is convex or part spheroidal in shape relative to the generallyhorizontal or straight surfaces of the manifold bottom 16. As a result,the central portion 28 is closer to the manifold bottom member 16 at itscentre compared with the periphery 30, where the spacing away from themanifold bottom member 16 is greater.

The convex shape of the underneath surface of the manifold top member 14(relative to the inside or cavity 54 of the manifold 15 as seen in FIG.4) results in a passage of larger cross sectional area being formedaround the outer periphery of the manifold 15 whilst a narrower orrestrictive passage is provided through the central portions of themanifold 15. This provides a relatively easy formed path for gas flowingfrom the gas supply connection 18 to the nozzle apertures 38, which inmost cases will flow around the manifold 15 circumferentially, but ifnecessary across the manifold through a convergent divergent path.

The cup 12 formed on the upper side of the manifold top member 14 alsoincludes the boss 32 which is raised from the central portion 28. Theboss 32 has its side wall extending downwardly, to form part of the rimwhich forms the recess 26. Two bores 34 pass through the boss 32. Thebores 34 allow a spark plug 36 and a flame sensor 37 to be positionedtherethrough. From underneath the manifold bottom member 16 appropriatecontrol wiring (not illustrated) is connected to the flame sensor 37 andthe spark plug 36 to generate a spark when a user desires to do so. Theboss 32 ensures that the spark plug 36, flame sensor 37 and associatedwiring does not pass through the cavity of the manifold 15.

Equi-spaced around the perimeter of the cup 12 or top surface of themanifold top member 14 are three nozzle apertures 38. The nozzleapertures 38 are threaded and each receive a male threaded injectornozzle 39. The injector nozzle 39 utilised will depend upon whether theburner 10 is utilised with town gas, natural gas or LPG.

Surrounding the nozzle apertures 38 are nozzle bosses 40. The purpose ofthe nozzle bosses 40 and the boss 32 is to protect the injector nozzles39, the spark plug 36 and flame sensor 37 from any food or liquid spiltthrough the burner and onto the cup 12. The dish shape or concave natureof the upper surface of the central portion 28 of the cup 12 is suchthat any liquid or food upon hitting the surface will tend to bedirected towards the centre of the cup 12 and thus away from theinjector nozzles 39, spark plug 36 and flame sensor 37.

Around the upper rim 42 of the manifold top member 14 are threeequi-spaced tapered notches 44 which will receive similarly shapedlocators 52 extending downwardly from the lowermost rim 88 or skirt ofthe distributor 50. It will be noted that the notches 44 are on the sameimaginary radius of the manifold top member 14 as the nozzle apertures38 so that the nozzle aperture 38 and notches 44 are aligned.

The manifold bottom member 16 is attached to the manifold top member 14by means of screws (not illustrated) spaced around the perimeter of themanifold bottom member 16. Any appropriate fixing system could beutilised such as riveting, clinching, bending the edge to form aretaining tag. If necessary, an appropriate sealant such as a gasket, orsilicone rubber could be used to seal the two pieces of the manifold 15together.

Also included in the upper rim 42 of manifold top member 14 are threemounting holes 48 which are used to secure the assembly of the manifoldtop member 14 and manifold bottom member 16 respectively into a stoveenclosure (not illustrated).

The distributor 50 is illustrated in more detail in FIGS. 5 and 6. Thedistributor 50 is made from aluminium or sintered steel and has aperiphery which is circular and a generally cylindrical outer wall 63.The periphery has three equi-spaced downwardly extending taperedlocators 52 that are on the same radius as a venturi passage in the formof a tapered bore 56. The tapered bore 56 makes up a portion of aventuri system provided in the distributor 50. The tapered bore 56begins from a relatively flat face 62 and proceeds to a transition port64 having a smaller diameter on an internal top surface of thedistributor 50. The other portion of the venturi system is a generallyhorizontal venturi portion made up of venturi extensions 78′ and 78″, aswill be described in more detail later. The transition port 64 is theport that is located in the venturi where the venturi is of minimumcross sectional area. The transition port 64 is also the location wherethe air gas mixture flow through the venturi changes from a generallyvertical flow to a generally horizontal flow.

The distributor 50 is of a generally annular or ring shaped constructionwith three radially inwardly projecting arms 58 which are of a taperedconstruction. This tapered construction provides the arms 58 with aminimum depth at their extremities 60 which increases to a maximum depthat a location radially inward of the base and inboard of the taperedbore 56.

Between the termini 60 of the radially inwardly directed arms 58 thereis provided an unobstructed space. This unobstructed space helps in thedistribution of heat to the surface of a wok or other cooking utensil.Further, each of the radially inwardly extending arms 58 has a portionwhich consists of essentially parallel sides.

The upper rim 66 of the generally cylindrical outer wall 63 terminatesin a single plane and completely surrounds the upper end of thedistributor 50. At three equi-spaced locations (these locations beingcircumferentially equidistant from the outlet ports 64), are locatedsegment-separating walls 68 which also terminate in the same plane asthe rim 66. The walls 68 interconnect rim 66 with the inner wall 70, theupper edge of which reaches the same plane as the wall 68 and rim 66.The inner wall 70, by virtue of the radial arms 58 forms a clover-leafshaped aperture through the distributor 50.

Through the inner wall 70 are a series of flame ports 72 of which onlyone has been numbered in FIG. 5, to maintain clarity of the drawing. Theflame ports 72 give the inner wall 70 a castellated appearance. It willbe noted that on the inner wall 70 between any two adjacent flame ports72 is another much shallower flame retention slot 74. The flameretention slot 74 helps to maintain a flame on the flame ports 72 whenthe distributor is in operation.

The tops of inner wall 70, between walls 68 and the interconnectingportion of the rim 66, being all in the same plane all make contact witha steel cap 80 positioned onto the top of the distributor 50. As isillustrated in the cross section of FIG. 4 or 7, the top of the innerwall 70, segment wall 68 and rim 66 will make contact with theundersurface of the cap 80 and will thereby form a series of flame ports72.

As is illustrated in FIG. 5 the longitudinal direction of the flameports 72 will result, for each segment of the distributor 50, in a flame84.1, which will form a flame pattern which is schematically depicted inFIG. 5. It will be noted that all the flame ports on the internalperiphery of the distributor 50 result in flames having a directionalcomponent which is directed internally of the distributor, but offsetfrom the centre of the distributor 50.

It will be noted from FIG. 5 that the flame ports 72 and for that matterthe flame retention ports 74 which are located on arms 58, are shown asbeing directed towards the centre of the distributor 50. One means forachieving this is for the ports 72 and 74 to be structured so that theaxis of the passage forming the port lies at an acute angle to theradial direction of extension of the arm 58. By this means a directioncomponent of the flame will be generally parallel to the direction ofradial extension of the arm 58 and further will be directed internallyof the distributor, albeit parallel to a radius from the geometricalcentre of the distributor 50.

Along a portion of the edge of the venturi extensions 78′, 78″, at theinterface between the circumferentially extending venturi extensions 78″and the radially inwardly extending venturi extension 78′, there isprovided two occluding ridges 50.4 and 50.3. The function of theseridges will be explained in more detail below, with reference to FIG.11.

As can be seen from FIG. 5 each burner segment, at a location adjacentthe rim 66, inner wall 70 and segment walls 68, has a channel 76. Thechannel 76 makes a circuit around the periphery of the burner segment.It can be seen from FIG. 5 that a crescent crossed T shaped arrangementis formed from the venturi extensions 78′ and 78″, whose vertical wallsform the inner wall of the peripheral channel 76.

It will be noted from the cross section of FIG. 4 that the venturiextensions 78′ and 78″ terminate at a level or height above the channelbase 82 which is below the plane containing the termination of the rim66, walls 68 or inner wall 70. This construction means that any gaspassing out of the manifold 15 via the nozzle apertures 38 and theinjector nozzles 39, will travel upwardly through the tapered bore 56and whilst doing so will entrain primary air (see arrows 200 asillustrated in FIG. 7). The air gas mixture will pass out of thetransition port 64 and travel in the generally horizontal directions ofarrow 83 in FIG. 7, the crossed arrows 84 of FIG. 5, and the arrow 84into and out of the page of the drawing along the circumferentiallyextending venturi extension 78″ in FIG. 7, thereby pressurising thechannel 76 with an air gas mixture. The upper horizontal surface of theventuri extensions 78′ and 78″ act as a horizontal venturi which assistswith the uptake of primary air.

The venturi extensions 78′ and 78″ extend in three directions away fromthe transition port 64. The venturi extensions 78″ extend in twocircumferential directions which are generally opposite to each otherand concentric to the rim 66, while the third venturi extension 78′extends in a radially inward direction along the radially inwardlydirected arms 58.

As can be seen from FIG. 7, the gas represented by arrows 200.1 entersthrough the female connector 18. This gas passes through manifold 15 andwhen ejected from injector 39 will entrain the primary air representedby arrows 200.5 (from the side edges of the air inlet ports 86) to forman air gas mixture 200 which is used for combustion (see dotted arrows200.3) at the flame ports 72 as illustrated in FIG. 4.

Once one flame port 72 has the exiting air gas mixture ignited by meansof the spark plug 36, all the rest of the flame ports 72 will catchalight and a flame pattern as schematically depicted in FIG. 5 willresult.

The lower rim of the distributor 50 has three equi-spaced air inletports 86 which have the centre aligned with the segment walls 68. Theair inlet ports 86 allow secondary air represented by arrows 200.2 topass from outside to the inside of the distributor 50 and thus beentrained and combusted with the air gas mixture.

Each air inlet port 86 is of a generally diverging then converging shapewhen viewed in the circumferential direction around the outside of thedistributor 50. This diverging then converging shape means that thecentre portion of the air inlet port 86 is of a greater cross sectionalarea than the extremities and is located so as to be immediately belowand outboard of the circumferentially located flame ports 72, the flameports 72 being located along the left and right sides of consecutiveradially inwardly extending arms 58. Thus through the main or centralcross sectional area of the air inlet port 86, the bulk of air flowingthrough the air inlet port can be used as secondary air for the burner,whereas at the reduced cross sectional area sections at the left andright extremities of the air inlet port 86, the air passing throughthese portions will travel circumferentially (see arrows 200.5 of FIG.7) once within the confines of the distributor 50 and thus travel to theinjector 39 to be entrained as primary air in the venturi passage ortapered bore 56.

The distributor 50 has its lowermost rim 88 between the air inlet ports86 in contact with the upper rim 42 of the manifold 15, therebygenerally preventing air passing directly underneath the rim 88 and intothe injector 39. This feature prevents any drafts from adverselyinfluencing the injector and its operation in entraining primary air andmixing same with gas.

It will be noted that there is one air inlet port 86 for each injector39 and that between the left and right extremities of adjacent air inletports 86, in approximately the centre thereof, is located the injector39 which is also positioned by the inboard side of wall 63 of thedistributor 50.

While the air inlet ports 86 in the FIGS. 1 to 7 are illustrated ascircular segments, other shapes could be utilised including eye-shaped,diamond shaped, triangular, half eye-shapes or half diamond shapes.These could be provided as cut-outs or as a hole with a complete rimthrough the wall 63 of the distributor 60.

The distributor 50 rests on the cup 12 or manifold 15 by means of thelocators 52 being positioned within the shaped notches 44. This willalign the tapered bores 56 and outlet ports 64 over the nozzle apertures38 and associated injector nozzles (not illustrated). Having threeequi-spaced locators 52, will ensure the alignment of these features inany of the three possible orientations of the distributor 50 on the cup12. The size, shape and length of the locators 52 and notches 44 must bematched so as to ensure that the rim 88 makes contact with the manifoldperiphery 42, thus preventing air flow underneath rim 88.

The lowermost rim 88 on either side of the locators 52 (the lowermostrim being the edge of the surface 62 of FIG. 6) will rest against theupper rim 42 of the manifold upper member 14. As can be seen from thecross sections of FIG. 4, a gap indicated by the distance 90 in FIG. 4will be located between the flat surface 62 and the upper surface of thenozzle bosses 40. This gap will allow air to be entrained by gas flowingfrom the injector nozzles 39 when the burner is assembled and connectedto a supply of gas.

The manifold 15 can be manufactured from aluminium and an appropriategas tight seal provided between the manifold bottom member 16 and themanifold top member 14. For cleaning purposes there is no securing ofthe distributor 50 onto the manifold 15 and the cap 80 is not secured tothe distributor 50 for the same reason.

While wall 68 is provided to segment the distributor 50, it is expectedthat such a segment wall 68 could be removed. If the wall 68 were notpresent, and assuming the influence of equal gas pressure emanating fromthe injectors nozzles via transition port 64 and over the venturiextensions 78′ and 78″, it is envisaged that the flow of gas willfunctionally segment the distributor 50 with similar effect as currentlyresults by means of the segmented wall 68.

If desired the number of radially inward arms 58 can be reduced to twoor increased to four, five or six depending upon the outside diameter ofthe distributor 50.

Illustrated in FIG. 8 is a modified distributor 250, which is similar tothe distributor 50, with like features being like numbered. Thedifference between the distributor 250 and the distributor 50 is thatthe portion of the channel 76 which runs adjacent to the rim 66 isabsent in the distributor 250, and thus the channel 76 is only adjacentthe inner wall 70 in the distributor 250. Another difference is thatoccluding ridges 50.4 and 50.3 are not utilised.

Illustrated in FIG. 9 is a modified distributor 350 which is similar tothe distributor 50, and accordingly, like parts have been like numbered.The difference between the distributor 350 and the distributor 50 isthat the distributor 350 has radially outwardly directed flame ports 72and retention ports 74 in the outer circumference or rim 66. The ports72 and 74 through rim 66 are approximately the same size as the ports 72and 74 on the internal perimeter of the distributor 350. Ports 72 and 74through rim 66 help to increase the thermal output of the assembledburner.

Another difference is that there are separate walls 68 forming theterminus of each segment. Between the adjacent walls 68 is a crosslighting passage 350.3. The purpose of the passage 350.3 is to allowcross lighting or flame propagation from inside the burner to the ports72 and 74 through rim 66 when the inwardly directed ports are ignited.

A further difference is the lack of occluding ridges 50.4 and 50.3 whichare present on the distributor 50. The distributor 50, whilst havingflame ports 72 through the rims 66, does not have any flame ports in theregion immediately above locator 52 and radially outwardly from the arm58. What is present however are flame retention ports 74. This allows atrivet to be utilised with the burner and prevents heat being wasted, aswell as ensuring lighting of the ports 72 when the burner has beenturned down.

Illustrated in FIG. 10 is a distributor 450 which is similar to thedistributor 350 of FIG. 9. Like parts have been like numbered. Thedistributor 450 has some improvements when compared to the distributor350.

A first improvement is a broader flame propagating or cross lightingchannel 350.3 which has been provided with facing flame retention ports450.1. Each flame retention port 450.1 is located through a respectivesegment-separating wall 68 at the ends of each segment. The flameretention ports 450.1 help to maintain a flame in this area thusallowing flame to propagate from the flame ports on the internalperiphery of the distributor 450 to the flame ports on the externalperiphery.

Another point of difference is in the region of the venturi around thetapered bores 56 and the associated outlets 64. This is shown in moredetail in FIG. 11. From FIG. 10 it can be seen that the venturiextensions 78′ extend radially inwardly to the same degree as in thedistributor 350, but the distributor 450 has the circumferentiallyextending venturi extensions 78″ being curtailed and tapering off to thebottom 82 of the distribution chamber. It will also be noted that in thedistributor 450 the depth of the channels 76 between thecircumferentially extending venturi extensions 78″ and the inboardsurface of the rim 66, and between the radially extending venturiextensions 78′ and the inboard surface of the inner wall 70, are ofreduced in depth by comparison to the previously described distributors.

It has been found that the shortening of the circumferentially extendingventuri extensions 78″ helps to balance the pressure of the air gasmixture within the distribution chamber and provide a balanced flow ofair gas mixture through all ports. This helps to provide better controlof the flames and thus the heat output.

Illustrated in FIG. 11, near a portion of the edge of the venturiextensions 78″ and 78″ are three occluding formations being an outerlocated occluding ridge 450.2 and two similarly sized and shapedinwardly occluding ridges 450.3 and 450.4. It will be seen from FIG. 11that the occluding ridges are higher towards their centre and tapertowards their extremities. The occluding ridges 450.2, 450.3 and 450.4serve two functions. The first function is to direct the air gas mixtureexiting from the transition port 64 over the upper surfaces of theventuri extensions 78′ and 78″ in the two circumferential, and oneradial, directions of extension. A second function is to prevent anundesired amount of air gas mixture escaping through the five flameretention ports 74 on the external wall 66 which is achieved by theoccluding ridge 450.2 as well as out of the flame retention ports 74 onthe opposing internal peripheral walls 70 by means of the occludingridges 450.3 and 450.4.

It will also be noted from FIGS. 10 and 11 that the transition port 64at the end of the tapered bore 56 is provided with a radius or bevel64.1. It is expected that in some circumstances this radius or bevelmight improve flow of air gas mixture out of the tapered bore 56 andinto the horizontal portions of the venturi.

Illustrated in FIG. 12 is a burner 500 which is similar in constructionto previously described burners and has a distributor 550 which issimilar in construction to the distributor 450. The distributor 550differs from the distributor 450 in that the inwardly extending arms 58also extend upwardly at an angle of inclination of approximately 15° to30° above the horizontal.

Similarly in regards to FIGS. 14 and 15, a burner 600 has a distributor650, which is similar to the distributor 550 of the burner 500, exceptthat the inwardly extending arms 58 lie at an angle of declination ofbetween 15° to 30° below the horizontal. In respect of both the burners500 and 600, advantages such as angling of the trivets used with theburner might provide greater efficiency in heating of a wok or similarcooking utensil.

Illustrated in FIGS. 16 and 17 is a burner and trivet combination whichcan be assembled onto a hob. The trivet 700 is made up of threesimilarly shaped support arms 702 which have inclined upper surfaces 704for supporting a wok or other cooking utensil.

It will be noted from the plan view of FIG. 16 that the trivet arms 702are arranged so as to overlie the centre lines of the radially extendingarms 58. Further, as the trivet arm 702 passes over the external wall 66of the distributor 450 the leg 706 of the trivet arm 702 is adjacentthat portion of the external of the burner which is not provided withflame ports 72 but rather only has flame retention ports 74—see FIG. 11.By this arrangement the amount of heat transferred to the trivet 700will be kept as low as possible thus making as much heat energyavailable to heat the cooking utensil as is possible.

Illustrated in FIG. 18 is a schematic representation of a burner segment801 such as is utilised in the previous described distributors andburners. The segment has three arms, two being circumferentiallyextending from the transition port 64 in opposite directions and thethird being centrally located and extending radially away from thetransition port 64.

Illustrated in FIG. 19 is another burner segment 802 whereby the segment802 extends in three directions, two circumferentially and in oppositedirections with the third in a radially outward direction from thecentre located transition port 64. The segment 802 also includesformations 801.1 and 801.2

Illustrated in FIG. 20 is a burner segment 803, where extension awayfrom the transition port 64 is only in two opposite circumferentialdirections. The segment 803 also includes formations 801.1 and 801.2

Illustrated in FIG. 21, a segment 804 extends away from transition port64 in four generally opposite directions, being two circumferentialdirections and two in opposite radial directions. The segment 804 alsoincludes formations 801.1 and 801.2

The shapes of the burner segments 801, 802, 803 and 804 illustrated inFIGS. 18 through to 21 can broadly be described as, in the case of FIG.18: a T shape with a concave arcuate or circumferential cross bar; inthe case of FIG. 19: T shape with a convex arcuate or circumferentialcross bar; in the case of FIG. 20: an arcuate shape; or in the case ofFIG. 21: a cross shape with an arcuate or circumferential cross bar.

While the description above in relation to FIGS. 1 to 17 describes thatthe segments of the distributors are integrally formed in a single piecedistributor, if desired, the segments can be provided with interlockingor other joining mechanisms, whereby adjacent burner segments can bejoined together according to the duty of the assembled distributor andburner.

Accordingly, schematically represented in FIGS. 18 to 21 areinterlocking formations 801.1 and 801.2 at the ends of thecircumferentially extending portions of the respective segments. Theformations 801.1 and 801.2 allow the respective segments to be assembledwith three other segments, to form a complete distributor.

The interlocking formation 801.1 is an arrow shaped recess formed in thebottom of the segments 801, 802, 803 and 804 and is sized and shaped soas to receive the matching shaped, formation 801.2 which is an arrowshaped protrusion extending away from the segments 801, 802, 803 and 804on an adjacent segment. While arrow shaped formation 801.1 and 801.2 areillustrated, other joining mechanisms could be used such as bayonetfittings, hook formations, spigots and apertures, locked together bycirclips, etc.

If desired, either in combination with interlocking formations 801.1 and801.2, or as an alternative to them, the discrete segments of thedistributor can be held together by interaction with, or by contact witha burner cap, such as cap 80 of previous figures. Further if desired oras an alternative to this, the discrete segments could be held togetherby means of a circumferential strap or other circumferential bindingsystem.

The burner segment 801, 802, 803 and 804 of FIGS. 18 to 21, can becombined, mixed and matched with same shape or different shape segments,so as to provide a generally circular ring of flame with inward and oroutward radial extensions to help generate further heat.

As will be readily understood from FIGS. 19, 20 and 21 the venturisystems associated with these segments would have two, three or fourventuri extensions 78′ and 78″ extending away from the transition port64, so that the horizontal venturi portions can direct air gas mixturein the direction of the ends of the segments.

The above description show distributors made up of three segments whichare separated by segment walls 68, and having three inwardly extendingarms 58, and each segment has its own distribution channel and orchamber, injector and venturi associated therewith. However it will bereadily understood that any number of segments and inwardly extendingarms could be utilised, as is appropriate for the duty of the burner.

It is to be noted that if a segment has two, three or four extendingsections that the horizontal venturi has a corresponding number ofventuri extensions 78′ and 78″.

In the above described burners and distributors, the venturi extensions78′ and 78″ are illustrated as being formed as part of the distributor.Further, as is illustrated in FIGS. 10 and 11, the occlusion ridges450.2, 450.3 and 450.4 are also shown depending from the distributor.Finally, the flame ports 72 and flame retention ports 74 are shown asbeing formed in the distributor. If desired, each of these featurescould be formed in the base of a cap which will sit on top of thedistributor or alternatively could be formed by a combination of beingformed on the underside of the cap and on the distributor.

Illustrated in FIG. 22 is a burner 800, which includes a distributor 850and a correspondingly shaped cap 80.2, which differ from the previouslydescribed burners by a star shaped aperture 800.1 being provided insteadof the clover leaf shaped aperture of other embodiments. The star shapedaperture 800.1 is comprised of long sides 800.2 and short sides 800.3.The long sides 800.2 have a combination of flame ports 72 and retentionports 74, whereas the short sides 800.3 have only flame retention ports74 therein. By directing the main flames from flame ports 72 in an anticlockwise direction a spiral flame pattern will result due to thebuoyancy of the flame and its propulsion in an anti-clockwise direction.Like previous embodiments the flame port 72 are directed towards thecentre of the burner.

The burner 800 has the segmented distributor, a similar venturi andventuri extension arrangement structure as in previous embodiments.While flame ports are shown on the internal periphery of the burner 800,externally mounted flame ports could also be provided.

To assist this further in the spiral flame effect, the flame ports 72can also have their axis orientated at an angle of inclination above thehorizontal.

Illustrated in FIG. 23 is a cross section through a portion an arm 58 ofa burner wherein flame ports 72, venturi extensions 78′ and occlusionridges 450.2 and 450.3 are all formed as part of a cap 80. Thedistributor 950 has a crescent crossed T shape distributor channel,which across its width and length has full depth down to the base 82 ofthe chamber. The distributor 950 also includes a vertical venturipassage 56 with the corresponding transition port 64.

Illustrated in FIG. 24 is a cross section through a portion of an arm 58of a burner wherein flame ports 72, venturi extensions 78′ and occlusionridges, 450.2 and 450.3 are formed by a combination of formations on theunderside of the cap 80 and in the distributor 1050. The top half of theflame port 72 being formed on the cap 80, while the bottom half isformed on the distributor 1050. In FIG. 24 one occlusion ridge 450.3 isformed on the cap 80 while the other occlusion ridge 450.3 is formed onthe distributor 105. A top half of a venturi extension 78′ is formed onthe cap 80, while the bottom half is formed on the distributor 1050. Ifdesired the occlusion ridges 450.2 and 450.3 could both extend from thedistributor or both from the cap, or half from distributor and half fromcap.

It will be understood that the invention disclosed and defined hereinextends to alternative combinations of two or more of the individualfeatures mentioned or evident from the text or drawings. All of thesedifferent combinations constitute various alternative aspects of theinvention.

The foregoing describes embodiments of the present invention andmodifications, obvious to those skilled in the art, can be made theretowithout departing from the scope of the present invention.

The invention claimed is:
 1. A gas burner including: a distributor meanshaving at least three distribution chambers to distribute an air gasmixture around said distributor, each distribution chamber consisting ofthree distribution channels having a substantially “T” configuration;each distribution channel including a plurality of flame ports throughwhich said gas mixture can pass and be ignited; at least one injectorassociated with each of said distribution chambers to deliver gas to thedistribution channels; each of the injectors being positioned to injectgas into its associated distribution chamber via a an associated venturisystem including an upwardly directed passage and a transition port andwherein the distribution channels enable gas flow in at least threedirections away from said transition port and towards associated flameports, wherein the burner has an internal aperture, at least some of theflame ports being oriented towards the internal aperture, eachdistribution chamber including at least one transversely projectingdistribution channel which projects into the aperture, the transverselyprojecting channel including flame ports adapted to direct combustiongasses into the aperture.
 2. A burner as claimed in claim 1, wherein twoof the distribution channels of each distribution chamber extendcircumferentially.
 3. A burner as claimed in claim 1, wherein eachventuri system includes an upright inward tapering section in fluidcommunication with a transverse expanding section via the transitionport, the transverse expanding section being within the correspondingdistribution chamber.
 4. A gas burner as claimed in claim 1, whereineach distribution chamber includes a transversely extending distributionchannel.
 5. A burner as claimed in claim 1, wherein said distributormeans has a generally cylindrical outer surface.
 6. A burner as claimedin claim 1, wherein each distribution chamber has an inwardly extendingdistribution channel, the inwardly extending distribution channelsincluding associated flame ports and being circumferentiallyequi-spaced.
 7. A burner as claimed in claim 1 wherein each distributionchamber includes at least one outwardly extending arm.
 8. A burner asclaimed in claim 1, wherein the aperture has a clover leafconfiguration.
 9. A burner as claimed in claim 1 wherein saiddistributor means is segmented, whereby each segment has its owndistribution chamber and injector.
 10. A burner as claimed in claim 9wherein said distributor means is segmented by means of segment wallsbetween respective segments.
 11. A burner as claimed in claim 9 whereinsaid distributor means is segmented by means of gas flow from saidinjectors.
 12. A burner as claimed in claim 9 wherein said segments formone of the following: a cross shape with an arcuate or circumferentialcross bar; a T shape with a convex arcuate or circumferential cross bar;a T shape with a concave arcuate or circumferential cross bar.
 13. Aburner as claimed in claim 1 wherein the air gas distribution channelsof each distribution chamber form a T shape with an arcuate orcircumferential cross bar.
 14. A burner as claimed in claim 9, whereineach segment includes four air gas distribution channels which form across shape with an arcuate or circumferential cross bar.
 15. A burneras claimed in claim 1, wherein said burner includes a cap which ispositioned on top of said distributor means.
 16. A burner as claimed inclaim 15, wherein each distribution chamber includes a venturi extensionformed at least partially in the cap.
 17. A burner as claimed in claim1, wherein said flame ports are formed in one or more walls of saiddistributor means.
 18. A burner as claimed in claim 15, wherein saidflame ports are formed in the cap.
 19. A burner as claimed in claim 18,wherein each distribution channel has one or more occluding structuresassociated therewith for directing and or baffling said air gas mixturein its flow from said transition port to said flame ports.
 20. A burneras claimed in claim 19, wherein said occluding structures comprise awall or ridge like formation extending away from the transition port.21. A burner as claimed in claim 1, wherein said distributor means hasat least one air entry port per injector.
 22. A burner as claimed inclaim 21, wherein each air entry port is formed in a side wall of saiddistributor means.
 23. A burner as claimed in claim 22, wherein said airentry ports have a larger cross sectional area at intermediate regionsby comparison to side regions of said air entry ports.
 24. A burner asclaimed in claim 22, wherein each air entry port is positioned in thewall of said distributor means so as to be located proximate saidinjector.
 25. A burner as claimed in claim 24, wherein each saidinjector is shielded by a portion of a wall of said distributor means toprevent air passing in through said air entry port from disturbing theoperation of said injector.
 26. A burner as claimed in claim 22, whereinthe distributor includes at least three inwardly extending arms, andwherein said air entry ports are located between respective arms of saiddistributor means, and wherein respective injectors are located so thatthey are aligned with the direction of said arm.
 27. A burner as claimedin claim 1, wherein the distributor includes at least three inwardlyextending arms, and wherein said burner includes a trivet which isaligned with said arms, so as to overlie said arms.
 28. A burner asclaimed in claim 1, wherein the distributor includes at least threeinwardly extending arms, and wherein said arms have a flame portarrangement whereby the axis of said flame ports on a respective arm isgenerally at an acute angle to the direction of a respective arm.
 29. Aburner as claimed in claim 1, wherein the distributor includes at leastthree inwardly extending arms, and wherein said arms extend away fromsaid distributor means for at least a part of the length of the arm atan angle of inclination or declination away from an imaginary horizontalplane.
 30. A burner as claimed in claim 1, wherein said distributormeans is mounted on a manifold including a gas inlet which communicateswith a cavity in said manifold, each of said injectors being in fluidcommunication with the cavity to receive gas supply from the cavity. 31.A burner as claimed in claim 30 wherein a wall of said cavity is shapedsuch that the height of said cavity at the outer periphery is of aheight greater than at the centre of said cavity.
 32. A burner asclaimed in claim 30, wherein said manifold cavity has its top surfaceconcave in shape.
 33. A burner as claimed claim 1, wherein saiddistributor means has an internal aperture such that the distributormeans has an internal and an external perimeter, with inwardly directedports in said internal perimeter and outwardly directed ports in itsexternal perimeter.
 34. A burner as claimed in claim 16, wherein eachventuri extension is oriented so as to be generally horizontal.
 35. Agas burner as claimed in claim 1, comprising one distributor meanshaving at least three discrete distribution chambers therein, eachchamber having communication with flame ports and including a venturisystem to supply an air gas mixture thereto; said burner having a singlemanifold to conduct gas to respective injectors for each venturi systemfrom a single gas supply connection to said manifold, each of saidchambers having a transversely extending channel, which projects into aninner aperture of said burner, whereby between the ends of respectiveinwardly extending channels there is provided an unobstructed space. 36.A gas burner as claimed in claim 35, wherein each transversely extendingchannel includes at least two sides which are generally parallel.
 37. Agas burner as claimed in claim 35, wherein each chamber also includestwo oppositely extending circumferential or arcuate channels.
 38. A gasburner as claimed in claim 35, wherein said chamber also includes anoutwardly projecting channel.
 39. A gas burner as claimed in claim 38,wherein said burner includes a cap.
 40. A gas burner as claimed in claim39, wherein the distributor means or said cap includes a multiplicity ofsaid flame ports.
 41. A gas burner as claimed in claim 40, wherein saidflame ports are formed by a combination of formations located on saiddistributor means and said cap.
 42. A gas burner as claimed in claim 35,wherein each distribution chamber includes at least three venturiextensions which each define two peripheral channels and a transversechannel to deliver air gas mixture to flame ports.
 43. A gas burner asclaimed in claim 39, wherein said cap includes at least three venturiextensions which extends into said chamber to define a radial channeland two peripheral channels to deliver air gas mixture to flame ports.44. A gas burner as claimed in claim 35, wherein each said venturisystem includes a vertical passage which opens into at least onegenerally horizontal venturi extension which extends away from saidvertical passage in the direction of each distribution channel of saidchamber.
 45. A gas burner as claimed in claim 39, wherein each generallyhorizontal venturi extension is formed in said distributor means and/orin an underside of the cap.
 46. A burner as claimed in claim 35, whereinsaid distributor means is an assembly of separate or discrete segmentswhich are assembled or otherwise joined together.
 47. A burner asclaimed in claim 46, wherein said separate or discrete segments includeinterlocking formations thereon so that adjacent burner segments can beassembled together.
 48. A burner as claimed in claim 46, wherein saidseparate or discrete segments are held together as an assembly by meansof a interaction with a burner cap.
 49. A burner as claimed in claim 46,wherein a circumferential fixing means assists in holding or holds saidseparate or discrete segments together as an assembly to form adistributor.
 50. A gas burner including a distributor means consistingof three chambers to distribute an air gas mixture around saiddistributor means, said burner including a plurality of flame portsthrough which said gas mixture can pass and be ignited; each chamberhaving an associated injector, each injector being positioned to injectgas into its associated chamber via a respective vertically directedconverging passage terminating with an transition port which hascommunication with said chamber, a venturi being formed in part by saidconverging passage and said transition port with a final part of saidventuri being formed by at least one venturi extension which acts upon agenerally horizontal flow of said air gas mixture flowing from saidtransition port, said transition port having at or near its rim two ormore occluding structures associated therewith for directing and orbaffling said air gas mixture in its flow from said transition port tosaid flame ports.
 51. A burner as claimed in claim 50, wherein saidoccluding structures comprise a wall or ridge like formation extendingaway from said protrusion and or said protrusion extensions.
 52. Aburner as claimed in claim 50, wherein said occluding structures have acastellated appearance.
 53. A burner as claimed in claim 50, whereinsaid occluding structures are formed on said distributor means or in acap associated with said distributor means or by a combination of both.54. A burner as claimed in claim 50, wherein said flame ports are formedon said distributor means or in a cap associated with said distributormeans or by a combination of both.
 55. A burner as claimed in claim 50,wherein extending away from said transition port there are at least twoventuri extensions.
 56. A burner as claimed in claim 50 wherein saidocclusion structures are located near to the edges of said venturiextensions.
 57. A burner as claimed in claim 35, wherein the manifoldincludes upper and lower disc-shaped walls sealed together at theirperimeters to define an internal cavity via which gas is delivered toeach injector.